steve
Explanation
This comic riffs on the story of Adam and Eve from the Book of Genesis. In the biblical account, Adam and Eve are the first humans created by God, and their disobedience (eating the forbidden fruit) brings sin and death into the world -- the concept of "original sin."
The comic shows someone at the Tree of Knowledge holding a protest sign that reads "ADAM & EVE, NOT ADAM & STEVE!" -- a phrase historically associated with opposition to same-sex marriage. However, another character pushes back, asking if the protester understands what the sign actually means in context. The point being made is that in the original biblical story, Adam and Eve's actions doomed all of humanity to suffering and death.
The protester then changes their sign to read "ADAM & STEVE, NOT ADAM & EVE" -- because if the argument is about the consequences of Adam and Eve's choices (original sin, death, and suffering for all humanity), then perhaps it would have been better if it had been "Adam and Steve" instead, since they presumably wouldn't have been the ones to bring about the Fall of Man.
The humor mechanism is a logical reversal: taking a phrase used as a rhetorical weapon and turning it on its head by following its own internal logic to an unintended conclusion. The protester's slogan backfires because, within the biblical narrative itself, Adam and Eve are actually the villains of the story. The comic cleverly inverts the original homophobic catchphrase into an argument against itself, using the protesters' own religious framework.